If I understand how this worked correctly, the original arcade cabinet had a joystick that could twist around in a complete circle, on top of moving in the normal 8 way direction. What that meant for this game was that moving it normally moved the character forward(starting off facing up), backward, and strafing Left/Right. You then needed to rotate the joystick until you were facing the enemy. This is such a pain to emulate(unless you actually have a joystick that works like this) that I'd have to recommend getting the joystick hack clone rom, which makes the character move in the direction you press. Otherwise, you'd have to use the mouse for turning...

A unique touch is that enemies will stay on screen, in the position in which you knocked them out(which you can see in the image above).